Calculating pen



FIG. 1 is a bottom front perspective view of a calculating pen;

FIG. 2 is a right side elevation view of the calculating pen of FIG. 1;

FIG. 3 is a front view of the calculating pen of FIG. 1;

FIG. 4 is a back view of the calculating pen of FIG. 1;

FIG. 5 is a bottom plan view of the calculating pen of FIG. 1; and,

FIG. 6 is a top plan view of the calculating pen of FIG. 1. 

The ornamental design for a calculating pen, as shown and described. 